New Single-Phase Bridgeless High-Voltage-Gain SEPIC PFC Converters with Improved Efficiency

Bridgeless power factor correction circuits are creditable for its merit of reducing conduction losses in semiconductors. In this paper, three new bridgeless single ended primary inductor converter (SEPIC) PFC converters by adopting switched-capacitor (SC) cell are proposed. Owing to the inbuilt SC cell, higher voltage gain can be generated than conventional SEPIC PFC converter. Compared to its conventional full-bridge counterparts, the proposed bridgeless SEPIC PFC converters feature a reduced conduction losses in semiconductors under the same operation parameters, contributing to improved efficiency. Furthermore, the proposed bridgeless SEPIC PFC converters adopt simple circuit structure. In addition, the proposed bridgeless SEPIC PFC converters are designed in discontinuous conduction mode (DCM) with the merits of inherently current-sharping capability and zero-current switching in semiconductors. The simulation results are provided in order to verify superiority of the proposed bridgeless SEPIC PFC converters.